The purpose of this MPA assessment benthic survey in Orkney waters (Rousay to Copinsay, including Eday Sound, and points in Scapa Flow) was to improve knowledge of the occurrence and distribution of species and habitats of recognised conservation importance, particularly priority marine features (PMFs). This survey is part of the SNH and MS MPA assesment of Scotland 2011. Underwater video tows and day grab sampling were conducted by Heriot-Watt University for MS from the 1st to 11th September 2011 to collect detailed biological information on the seabed species and habitat features present and aid biotope assignments to each station. Diver MNCR surveys were conducted at sites where healthy Modiolus modiolus and Mearl beds were observed on video, and diver core samples taken to investigate infauna and PSA. Analyses of the seabed video and still photographic imagery were used to describe the nature of the seabed in terms of the physical structure and the species assemblages.